Atkins had been looking to fill the subordinate post of chief operating officer with the intention of promoting the successful applicant to chief executive next year.
It has been forced to change this plan after its recruitment consultant said that it would deter high-calibre executives. The company has now drawn up a shortlist of six for the post of chief executive.
Mike Jeffries has been filling the roles of chairman and acting chief executive since October, when Robin Southwell departed after Atkins issued a surprise profit warning.
Jeffries drew up his first shortlist in November, and those on that list were interviewed in January.
Atkins' recruitment consultants have since held about 20-30 external interviews for the second shortlist. These candidates will then be interviewed by the board this month. At least one of the shortlisted candidates has little or no background in the sector – like Southwell.
It is understood that Atkins wants to make an appointment by July, when its preliminary year-end results will be announced.
Jeffries would not confirm this, but said: "There has been no shortage of interest in the post. The search is going on.
"We have internal targets on when the appointment should be made, but it is more important to make the right choice."
The salary of the chief executive will be open to negotiation. Southwell earned £350,000 a year.
Before joining Atkins, Southwell was in charge of BAE Systems in Australia. He is now chief executive of European aerospace consortium AirTanker.
Atkins said that the fall in the amount of debt was a result of the normalisation of supplier payments, which had been hit by an IT systems failure last year, and the payment of restructuring costs.